1. Field of the invention
This invention relates to a novel crystalline saccharide, and its production and use, more particularly, to a crystalline maltotetraosyl glucoside, and to its production and use.
2. Description of the prior art
Maltopentaose is a penta-saccharide represented by the general formula of O-.alpha.-D-glucopyranosyl-(1.fwdarw.4)-O-.alpha.-D-glucopyranosyl-(1.fwda rw.4)-O-.alpha.-D-glucopyranosyl-(1.fwdarw.4)-O-.alpha.-D-glucopyranosyl-(1 .fwdarw.4)-D-glucopyranose, and has been known as a sweetener which is incorporated into starch syrup or its powder. This saccharide is characteristic of its low sweetness and appropriate viscosity, and used in compositions including beverages, foods and tastable products such as tobacco and cigarette. Since maltopentaose is a reducing saccharide, however, it has the drawbacks that it readily causes browning reaction along with proteins and amino acids contained in beverages and foods to induce the deterioration and degeneration of these products.
The present inventors have energetically studied means to overcome the drawbacks and found that the preparation of a non-reducing maltotetraosyl glucoside from maltopentaose is obtainable by exposing a reducing partial starch hydrolysate having a glucose polymerization degree of 3 or higher to the action of an enzyme capable of forming a non-reducing saccharide having a trehalose structure as an end unit (hereinafter called "a non-reducing saccharide-forming enzyme" in the specification), Suehas those disclosed in Japan Patent Application No.349,216/93. However, such a non-reducing saccharide of maltotetraosyl glucoside is in powdery form which is amorphous and unstable physically, and for the sake of stability the establishment of a crystalline maltotetraosyl glucoside has been desired.